pH Dropping..

[inthetrees]

Hey guys,

Wondering if anyone has had any pH issues in UC/RDWC when going from veg to flower? I was feeding 800ppm in veg and things were perfect. pH was drifting up, plants were drinking a ton, ppm's were slowly dropping.

I lollipopped and cleaned the canopy the day I flipped and it was business as usual for the next two weeks. I then did another clean up and the end of week 2. Then things kinda got weird after that...Everything flipped upside down.

pH started dropping, ppms rising. Plants were drinking but went from 6 - 8 gallons per day down to 4. I figured this was from removing so much of the bottom growth. Less plants = less nutes needed. As per the chart posted on here, those signs were pointing towards the nutrient solution being too high. I flushed the systems and dropped to 650 ppm. PPm's dropped about 50 -60 and ph rose slightly all within 4 hours, then it was back to ph dropping and ppms rising. Ph would drop from 5.7 to 4.7 overnight. I adjusted the pH upwards for 2 days then said screw it and flushed again this time dropping to 500 ppm.

Once again the systems dropped 50 - 60 ppm in the first few hours and the cycle started again. It's slower this time now. lights went out and pH was 6.2, woke up to 6.1 and ppms from 460 to 430. Now the ppms seem to be dropping ever so slightly however the pH is creeping down.

I'm at a loss as to what's going on. I've spent the last week going over every single thread on every forum trying to find an answer. There are quite a few people who have experienced the exact same thing as I am seeing. Everything fine in veg, high ppms, then 2 or 3 weeks into flower it all crashes and the plants want half of what they were eating before. I haven't found a solid answer though. There's been a few guys saying that its a salt buildup and to flush the systems with straight water for 24 - 48 hours but to me that doesn't make sense. Where would the salt build up be? I've flushed the systems every 7 - 10 days. It's UC not soil. Everything points to root rot or pythium but I'm running DIY Uc Roots @ 7ml/gal and adding in more every 3-4 days. My water temps are also at 66F. Environment has been static with canopy temp @ 82-85F, ambient room @ 75F and Humidity @ 65%. My roots have a brown tinge but its a stain from the nutes. There's no slime, gunk on bulkheads, or bad smell.

The only thing I've been not been able to control is cooling the room at night. I got a 50 pint dehumidifier and it will drop the room to 45% but the heat is keeping the overnight temps at 75F. I'm just waiting on a 6" damper to show up so I can setup a fresh air intake/exhaust with a temp controller for lights off. Aside from that nothing has changed.

I'm lost as to how these plants were eating 800+ ppms in the systems and the top offs at 1100 ppm to compensate, yet now I have the systems and top offs @ 500 going into week 4 and the pH is still dropping a bit. I could keep compensating by adding pH up but I feel like thats just a bandaid and I want to know wtf is going on or what has changed. I'm going to see how things so over the next 24 hours, but if I see a ph drop over the next 24 hours all I can think to do is drop down more. I have 2 separate systems with 2 different strains experiencing the exact same thing. Idk wtf else to do.

 

[inthetrees]

To me it seems like there's something I'm short on in my mix. Both flushes the systems have that 50 - 60 ppm drop within 4 hours as if they are sucking up what I'm assuming is P&K, then they are waiting for the top offs to replenish the amounts. Doesn't make sense though considering I'm running Remo MIcro/Bloom/Calmag and adding in the lowest recommended dose of liquid koolbloom as a pk booster since I cut out remos boost. I was also running twice as much of the koolbloom as I am now for the first 2.5 weeks and saw ppms dropping.

Wondering if I should cut back the calmag and micro but add in more of the bloom + liquid kool bloom. Ill keep the ppms at 450 - 500 and see what happens...

 

[SoLowDoughLow]

To me it seems like there's something I'm short on in my mix. Both flushes the systems have that 50 - 60 ppm drop within 4 hours as if they are sucking up what I'm assuming is P&K, then they are waiting for the top offs to replenish the amounts. Doesn't make sense though considering I'm running Remo MIcro/Bloom/Calmag and adding in the lowest recommended dose of liquid koolbloom as a pk booster since I cut out remos boost. I was also running twice as much of the koolbloom as I am now for the first 2.5 weeks and saw ppms dropping.

Wondering if I should cut back the calmag and micro but add in more of the bloom + liquid kool bloom. Ill keep the ppms at 450 - 500 and see what happens...

I used to get this issue a lot too. One thing that helped me is obviously discovering the ratios of npk that each plant likes. My advice is to be super careful with any bloom boosters as it's really easy to get lockout. But also, top feeding through the hydroton helped out some because I assume nutes were building up and nothing was washing it away.

 

[Streetpro09]

To me it seems like there's something I'm short on in my mix. Both flushes the systems have that 50 - 60 ppm drop within 4 hours as if they are sucking up what I'm assuming is P&K, then they are waiting for the top offs to replenish the amounts. Doesn't make sense though considering I'm running Remo MIcro/Bloom/Calmag and adding in the lowest recommended dose of liquid koolbloom as a pk booster since I cut out remos boost. I was also running twice as much of the koolbloom as I am now for the first 2.5 weeks and saw ppms dropping.

Wondering if I should cut back the calmag and micro but add in more of the bloom + liquid kool bloom. Ill keep the ppms at 450 - 500 and see what happens...

I'd be curious to know what you figure out. I'm running into a similar problem but not until week 5-6. No sure what to do either. It's like they hit a wall. Mine arent showing any signs on the leaves of nutrient problems. What about yours? How do the plants look? I kinda like SoLows idea of pouring water through the net pots. Not so sure it would make a difference but I might give it a shot and see what happens. I'm currently down in the 500 ppm range instead of 800.

I was originally thinking that the plant must not need that many nutes toward the end but now you got me thinking.

 

[inthetrees]

I found an old thread specific to guys growing in Current culture systems. Some guys saying to push the plants until you hit that balance point of ppm and pH stabilizing but water levels dropping. Other saying that CC is bang on and to follow their recommended numbers by keep the ppms low. Quite a few guys (including CC) saying not to go over 650 max in flower as the plants will suffer regardless of not showing signs of excess/burning.

I think your right @SoLowDoughLow I hit the wall in flower because of my ratios being off. Veg was good because I was feeding the right ratios and providing an abundance of calmag, micro, and nitrogen. Now that the plants needs have transferred to P&K I'm all sideways.

Looking at CC's recommendations I'm supplying a huge excess of cal-mag and my micro may be a bit high as well. They are suggesting 1 mL/gal max of cal-mag and I've been at 5-6mL/gal which is accounting for around 150 ppm. My micro is also at 6mL/gal but I'll have to look as to how many ppm that accounts for. That would explain why i see that 50 - 60 ppm drop immediately after flush and then shit goes south afterwards.

I'm not saying that my strains aren't capable of hitting those higher numbers, but the ratios have to be right to do so. I'm going to go flush one of the systems and revamp the nutrients. Less micro, way less calmag, and up the Remo Bloom and put it at 500 ppm. No Liquid Koolbloom additive.

The only reason I strayed from Remo's complete line was because my systems are sterile. I can't run their PK booster, carb additive, or Kelp products because of this. The Koolbloom and high cal-mag may be the culprits.

This would make sense to do as allot of guys (including Heisenbeans) and only running 2 part nutes with great success.

 

[inthetrees]

I'm also going to try and dump some water through the net pots and see if my ppms come up by chance...

 

[SoLowDoughLow]

I'd be curious to know what you figure out. I'm running into a similar problem but not until week 5-6. No sure what to do either. It's like they hit a wall. Mine arent showing any signs on the leaves of nutrient problems. What about yours? How do the plants look? I kinda like SoLows idea of pouring water through the net pots. Not so sure it would make a difference but I might give it a shot and see what happens. I'm currently down in the 500 ppm range instead of 800.

I was originally thinking that the plant must not need that many nutes toward the end but now you got me thinking.

Yeah I'm not too sure if it made a difference or not because I switched up a couple things at the same time but I can't see it hurting. And yeah I have just been going real low ppm in flower with better results. I haven't ran rdwc for a little bit, but I run dwc all year and I had those same issues. I have switched nutes a few times too though and certain ones don't have this problem

 

[Streetpro09]

Yeah I'm not too sure if it made a difference or not because I switched up a couple things at the same time but I can't see it hurting. And yeah I have just been going real low ppm in flower with better results. I haven't ran rdwc for a little bit, but I run dwc all year and I had those same issues. I have switched nutes a few times too though and certain ones don't have this problem

Yeah I run dwc. I just figured the characteristics were the same.

Now that I think about it more, this run did better with the ph going up and ppm going down from the beginning of flower till the start of week 6. I changed my ratios this run and now that we're taking about it that idea makes sense. Have any idea what ratio plants like in their last few weeks of life?

 

[inthetrees]

So as I was mixing up the nutrients I never thought to take a look at the PK booster bottles (Remo Astrobloom VS Koolbloom). The only difference is the KB has 6% more phosphorus. Remo is nice that no matter how much your feeding the measurements per additive are always the same. That being said I can't see it being incorrect ratios.

Anywho I have 100 ppm less calmag in the mixed solution (now at 50ppm using 2mL/gal) and I can put that 100 towards the PK and see if something changes. Going to hold off till tomorrow morning before flushing. See what the numbers say in the AM.

I also dumped 2 liters of solution from each system through the tops of the net pots. PPM's stayed the same but at least I've ruled out a salt buildup in the pots.

 

[inthetrees]

I'm completely lost... Both systems were between 6.0 - 6.2 ph at lights off last night. This morning at one was at 5.2 and the other was 4.6. Systems only drank 2 gallons and 3.5 which is down to to half of their usual intake.

I left the window open in the veg room so my night temps were 67F and 50% in the flower room. I thought maybe there was an issue with co2 getting into the root zone but the pumps are in the veg room with the window open and last night proves that theory is wrong.

I'm getting yellowing off of leaves and tips are crisping.

 

[inthetrees]

I found this online... It would explain why the chart on here for hydro reservoir explanations says to raise the EC if the ph, ppms, and water level are dropping...

"A falling ph with a rising EC is not the time to start adding just water.
I will explain why.
Your plants roots sort of have their own internal EC, which will be different from that of the water/nute solution.
So if the plants internal EC is LOWER than the solutions, the plant will absorb nutrients along with water.
If the plants roots however have a higher EC than the nute solution, they will leech nutrients and raise your nute EC.

So, if you have a static water level, with a rising EC, raise your nute EC.

If your water level is dropping and the EC is rising, this is when you need to add water to the nute solution.

This has not looked at the ph.

If your ph is falling in DWC, it generally means your EC is too low (as above). "

 

[inthetrees]

I have the one system at 500 ppm and i took the other system up to 850. Im going to see what happens. This has to be the issue as the roots look fine, my bulkheads and airstones are clean with no gunk or build up. this is my hail mary aside from flushing with straight water for 24 hours which id rather not do.

I looked back over my data and when shit started going south my ppms got down to 500, then they started to rise. I think i may have been starving the plants ffs. This goes against everything that current culture says but there's too many variables between strains and nutrients to take their word as the gospel. I'll check the systems in 4 hours and see what's happened.

Sorry for all the long posts. Hopefully I get this sorted out and this thread can help someone out in the future. Or you guys are front row to a very expensive car hitting a brick wall with the finish line in sight.

 

[inthetrees]

Whammo boys I got 'er beat. The plants were starving... Idk why I didn't look at my data better and see the trend. I had no idea that I could starve the plants at the same level that Current Culture is saying should be a max ppm. Less is not more, its a recipe for disaster. For me anyways.

Both systems are already down 3 gallons and dropped 150 ppm in 3 hours so they are playing catch up at an insane rate.

@Streetpro09 this might explain your week 5 and 6 issue if your had the same pH drop occurring. Makes sense as they would want much more in the start of late flower.

Thanks for the input and help everyone

 

[Streetpro09]

Whammo boys I got 'er beat. The plants were starving... Idk why I didn't look at my data better and see the trend. I had no idea that I could starve the plants at the same level that Current Culture is saying should be a max ppm. Less is not more, its a recipe for disaster. For me anyways.

Both systems are already down 3 gallons and dropped 150 ppm in 3 hours so they are playing catch up at an insane rate.

@Streetpro09 this might explain your week 5 and 6 issue if your had the same pH drop occurring. Makes sense as they would want much more in the start of late flower.

Thanks for the input and help everyone

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Awsome man. Glad to hear that. I'll be adding ppms to mine tonight and we'll see what happens.

 

[SoLowDoughLow]

Awsome man. Glad to hear that. I'll be adding ppms to mine tonight and we'll see what happens.

Yea, I got a bunch of Mac1 and gg4 clones going. I've been trying to dial them in. I think I'm gonna try this too because usually my water level is dropping but there have been a couple lately that have been static. It will be cool to compare the results of the different clones.

 

[Streetpro09]

Well bombs away on mine. I didn't really change the ppm drastically. Raised it by 50-75 in 4 buckets. I changed the radio though. Didn't add any calmag in the mix this time and made up those extra ppm with nutrients. We'll see how they are doing tomorrow. I'll have to check them in 4 hours just to see if there's a difference but the next couple days will tell the tale.

 

[Skunkle Justin]

I used to get this issue a lot too. One thing that helped me is obviously discovering the ratios of npk that each plant likes. My advice is to be super careful with any bloom boosters as it's really easy to get lockout. But also, top feeding through the hydroton helped out some because I assume nutes were building up and nothing was washing it away.

This is exactly what is happening. The bloom booster is causing lockout. So, the plant is drinking water but not up taking any of the nutes which causes the pH to drop. Too much K and then you get Calcium deficiencies so calmag gets added and locks out the potassium. And so on.

 

[SoLowDoughLow]

This is exactly what is happening. The bloom booster is causing lockout. So, the plant is drinking water but not up taking any of the nutes which causes the pH to drop. Too much K and then you get Calcium deficiencies so calmag gets added and locks out the potassium. And so on.

Do you use any bloom boosters? If so, when do you usually add them? I've been waiting until around week 5 with good success. I believe I was adding them too soon before, but I was wondering what other people's experience was...

 

[Skunkle Justin]

Do you use any bloom boosters? If so, when do you usually add them? I've been waiting until around week 5 with good success. I believe I was adding them too soon before, but I was wondering what other people's experience was...

I sure do but how much and when varies. The thing to remember about growing in DWC is that it is essentially a science experiment with your plants. You have to monitor the ppm and pH daily to see where the highs and lows are. This tells you how and when the plants are eating nutes and drinking water so you can adjust accordingly. I slowly add bloom boosters at the beginning of flower and slowly increase the dosage to about double during weeks 5-8. Then start backing down to the original dose by the end of week ten. And, no, I don’t flush because I dont use Miracle-Gro that burns the shit out of the plants and I do a long dry (10 days) and long cure (minimum of four weeks, preferably three months). Don’t ever ever ever starve your plants but after you’ve grown a specific clone out a few times, you’ll have the right feeding plan for it.

 

[SoLowDoughLow]

Well bombs away on mine. I didn't really change the ppm drastically. Raised it by 50-75 in 4 buckets. I changed the radio though. Didn't add any calmag in the mix this time and made up those extra ppm with nutrients. We'll see how they are doing tomorrow. I'll have to check them in 4 hours just to see if there's a difference but the next couple days will tell the tale.

I can confirm that raising the ppm in my plants with a static water level and rising ppms seemed to do the trick. I was around 600 ppm and rising with static water levels so I increased my ppm to around 870 and it dropped to 700 by the next morning.